Biology

Genetics and Evolutionary Biology

1,123 Questions

Genetics and evolutionary biology explain how traits are passed from parents to offspring and how species change over time. Key concepts include genetic drift, inbreeding, and heredity. This topic is fundamental for the biology section of many competitive tests.

Heredity and traitsGenetic variations and driftInbreeding conceptsEvolutionary mechanisms

Genetics and Evolutionary Biology Questions

Multiple choice

Which of the following measures clinical validity?

  1. The likelihood that a mutation stated to be present is in fact present.

  2. The likelihood that identification of a mutation correctly predicts presence or absence of disease.

  3. The likelihood that a mutation test will successfully identify a pathogenic mutation.

  4. The likelihood that an identified mutation is pathogenic vs. a benign variant.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Clinical validity is the likelihood that a mutation correctly predicts the presence or absence of disease.

Multiple choice

Which of the following statements is TRUE?

  1. All genetically inherited characters have a clinal dissipation.

  2. Human biological races really exist.

  3. Of the three models of human variation, the clinal one comes closest to grabing the real nature of human variation.

  4. All genetically inherited characters have a typological distribution.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The typological model is scientifically unsound. The populational model is theoretically sound but of little value since we do not have distinct breeding populations. Only the clinal model explains most of human variation as we know it to be.

Multiple choice

The clinal model of human variation signifies the fact that

  1. genetically inherited characters will slowly change in frequency among the people you encounter as you travel from one geographic area to another

  2. genetically inherited characters will abruptly change in frequency as you go from one population to another

  3. there lies no significant difference in the frequency of genetically inherited characters among the population of the world

  4. genetically inherited characters will drastically change in frequency among the people you encounter as you travel from one geographic area to another
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Advocates of this model construct clinal maps to visualize the gradual changes. An example is the clinal distribution of the B blood type allele in Europe.

Multiple choice

Evolutionary processes that may change the frequency of genetically inherited characters in present human population, usually include

  1. natural selection

  2. social selection like discrimination in choosing a spouse

  3. migration

  4. all of the above
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Natural and social selection are very strong forces that can operate at the same time. There also can be the introduction or removal of genes from a population due to migration. In addition, genetic drift and other processes may be determining factors.

Multiple choice

Which of the following facts signifies the variation of population model of human?

  1. Each continent of the world is the home of a distinct race only.

  2. Mongoloids, Negroids, and Caucasoids are divergent species of people of today's world.

  3. If geographic and cultural obstructions to mating break down previously isolated populations will cease having distinct sets of physical traits setting them apart.

  4. Biologically distinct groups of individuals are those which had been gone through short breeding isolation.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The populational model assumes that the only biologically distinct groups of people are those that have long breeding isolation. When the isolation breaks down, the genetic distinctness of such groups also ceases.

Multiple choice

Our own personal physical characteristics are the consequence of

  1. genetic inheritance

  2. certain environmental factors shaping our bodies as we grow from childhood to adulthood

  3. genetic inheritance primarily but with some shaping by environmental forces as we grow from childhood to adulthood

  4. random chance
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

We are mostly the product of the combination of genes that we inherited from our parents. However, environmental influences also have an effect. For example, severely undernourished children are not likely to reach their full potential stature.

Multiple choice

The augmenting frequency of yellow-brown hair among Australian aborigines as one moves inland from the southwest coast of Australia is an example of

  1. random variation

  2. progressive gradation

  3. discontinuous distribution

  4. natural selection
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The gradual, more or less continuous change in hair colour from one group of aborigines to another is not random or haphazard. There probably is a progressive gradation because there are different evolutionary pressures from one region to another.

Multiple choice

The isolated pockets of red-haired people in the British Isles is an example of discontinuous distribution. This distribution pattern is most likely the consequence of

  1. voyaging of red-haired people

  2. natural selection favouring red hair

  3. random mating

  4. random variation
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

This distribution pattern is most likely the result of migration of groups of red-haired people into areas where other hair colours pre-dominated. However, it could also result from discriminatory marriage partner selection.

Multiple choice

Which of the following options is not a desired trait for raising new variety of poultry breeds?

  1. Number and quality of chicks

  2. High maintenance requirements

  3. High tolerance to extreme temperatures

  4. Reduced size of birds
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Reason: A high maintenance requirement is not a desired trait for raising new variety of poultry breeds. The cross breeding programmes between Indian (indigenous breed like Aseel) and foreign (leghorn) breeds for variety improvement are focused on developing new varieties for the following desired traits: - Number and quality of chicks - Dwarf broiler parents for commercial chick production - Summer adaptation capacity/tolerance to high temperature - Low maintenance requirements - Reduction in the size of egg laying birds with ability to utilize more fibrous and cheaper diets formulated using agricultural by-products

Multiple choice

Variations cannot occur due to _____.

  1. crossing over

  2. mutation

  3. effect of environment

  4. asexual reproduction
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Asexual reproduction produces genetically identical offspring through mitotic cell division, without the genetic recombination that occurs during sexual reproduction. This lack of meiosis and genetic mixing means significant variations cannot arise through asexual reproduction alone.

Multiple choice

Phenotypic appearance of each individual is unique because

  1. entire DNA of all individuals is different

  2. repetitive sequences of each individual are unique

  3. telomeres of each individual are unique

  4. size of chromosomes of each individual is unique
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Repetitive sequences of each individual are unique.